采用快速液相烧结法制备Bi_(1-x)Pr_(x)Fe_(1-x)Ti_(x)O_(3)(x=0.00、0.03、0.06、0.12)系列多铁陶瓷样品,研究Pr-Ti共掺杂对BiFe O_(3)结构、缺陷、电学和磁学特性的影响。XRD分析结果表明:所有样品均为菱方钙钛矿结构,Pr-Ti共掺杂可...采用快速液相烧结法制备Bi_(1-x)Pr_(x)Fe_(1-x)Ti_(x)O_(3)(x=0.00、0.03、0.06、0.12)系列多铁陶瓷样品,研究Pr-Ti共掺杂对BiFe O_(3)结构、缺陷、电学和磁学特性的影响。XRD分析结果表明:所有样品均为菱方钙钛矿结构,Pr-Ti共掺杂可有效抑制杂相生成,当掺杂量高于0.06时杂相基本消失,共掺杂引起结构畸变。正电子湮没寿命谱测试结果表明:所有样品中均存在阳离子空位型缺陷,空位尺寸和浓度均随Pr-Ti掺杂量增加而增大。电学和磁学性能测试结果表明:适量Pr-Ti共掺杂可有效提高Bi Fe O_(3)的介电、铁电和磁学性能。综合上述结果,认为BiFeO_(3)多铁性能的改善可能是由于Pr-Ti共掺杂引起晶格畸变、减少氧空位浓度、改变阳离子空位浓度等多种原因引起。展开更多
Recently,high-performance lead zirconate titanate(Pb(Zr_(1-x)Ti_(x))O_(3),PZT)ferroelectric ceramics have attracted intensive attention due to their wider operating temperature range,better temperature stability,as we...Recently,high-performance lead zirconate titanate(Pb(Zr_(1-x)Ti_(x))O_(3),PZT)ferroelectric ceramics have attracted intensive attention due to their wider operating temperature range,better temperature stability,as well as larger piezoelectric properties and higher energy conversion efficiency.In this study,the perovskite-type ferroelectric ceramics with a chemical formula of Pb_(0.99-x)Gd_(0.01)Sr_(x)Zr_(0.53)Ti_(0.47)O_(3)(x=0 and 0.02,abbr.PGZT and PGSZT,respectively)were prepared by the traditional solid-state reaction route.The influences of Sr-doping on the phase structure,dielectric properties,ferroelectric properties and piezoelectric properties of the PGZT ceramics were comprehensively investigated.The field-dependent P–E hysteresis loops of PGSZT were measured in the frequency range of 0.05–10 Hz and temperature range of 20–100℃.The results show that Sr-doping not only enhances the dielectric permittivity and piezoelectric coefficient of PGZT,but also decreases its dielectric loss tangent,with the d_(33) value of 473 pC/N,ε_(r) value of 1586 and tanδvalue of 0.016 found in PGSZT.Also,PGSZT shows a high Curie temperature(T_(C))of 350℃.The underlying mechanisms of the property enhancement were identified as that the introduced Sr^(2+) replaces the volatile Pb^(2+) located at the A-site of the perovskite structure,thereby reducing the concentration of lead vacancies and promoting the grain growth of the ceramics,consequently enhancing the dielectric and piezoelectric properties of PGZT.On the other hand,the frequency change in the low-frequency range(<1 Hz)played a significant impact on the remanent polarization(P_(r))and internal biased electric field(E_(i))of PGSZT,but the frequency dependence of coercive field(E_(c))tends to diminish in the high-frequency range(≥1 Hz).展开更多
Pr_(2)(Zr_(1−x)Ti_(x))_(3)(MoO_(4))_(9)(x=0.1-1.0)ceramics were prepared via a conventional solid-state method,the dependence of crystal structure and bond characteristics on microwave dielectric properties was invest...Pr_(2)(Zr_(1−x)Ti_(x))_(3)(MoO_(4))_(9)(x=0.1-1.0)ceramics were prepared via a conventional solid-state method,the dependence of crystal structure and bond characteristics on microwave dielectric properties was investigated systemically.The X-ray diffraction patterns indicated that the single-phase Pr_(2)Zr_(3)(MoO_(4))_(9)structure was formed in all the specimens.As the Ti^(4+)content increased,the lattice volume gradually decreased,which was ascribed to the fact that the ionic radius of Ti^(4+)was smaller than that of Zr^(4+).Notably,outstanding microwave dielectric properties withεr of 10.73-16.35,Q·f values of 80,696-18,726 GHz and minorτ_(f) values−14.1-−2.6 ppm/℃were achieved in Pr_(2)(Zr_(1−x)Ti_(x))_(3)(MoO_(4))_(9)ceramics.Theε_(r) increased with the rising x values,which was associated with the increase ofα/Vm values.The decreasing Q·f was affected by the decline of lattice energy of[Zr/TiO_(6)]octahedral.Theτf value was dominated by[Zr/TiO_(6)]octahedral distortion,Mo-O bond energy,bond strength and B-site bond valence.Furthermore,infrared reflection spectra suggested that the properties were mainly caused by the absorption of phonon,and the dielectric loss could be further reduced by optimizing the experimental process.展开更多
Rare earth Er^(3+)doped(Sm_(1-x)Er_(x))_(2)Zr_(2)O_(7)(x=0.1,0.2,and 0.3)ceramic samples were synthesized using a solid state reaction method.The microstructure and thermal properties of these ceramics were investigat...Rare earth Er^(3+)doped(Sm_(1-x)Er_(x))_(2)Zr_(2)O_(7)(x=0.1,0.2,and 0.3)ceramic samples were synthesized using a solid state reaction method.The microstructure and thermal properties of these ceramics were investigated to evaluate their potential as thermal barrier coating materials.The results show that ceramics are compact with regular-shaped grains of 1-5μm size.(Sm_(1-x)Er_(x))_(2)Zr_(2)O_(7)has a pyrochlore structure mainly determined by ionic radius ratio,but the ordering degree decreases with increase of the Er_(2)O_(3)content.There is no phase transformation from 1000 to 1200℃,and the(Sm_(1-x)Er_(x))_(2)Zr_(2)O_(7)ceramics exhibit excellent phase stability during thermal treatment at 1200℃for 100 h and 1400℃for 50 h.The thermal conductivities of dense(Sm_(1-x)Er_(x))_(2)Zr_(2)O_(7)ceramics range from 1.52 to 1.59 W/(m·K),which is lower than that of Sm_(2)Zr_(2)O_(7),and decrease as the Er2O3content increases.Besides,the thermal expansion coefficient of(Sm_(1-x)Er_(x))_(2)Zr_(2)O_(7)is higher than that of Sm_(2)Zr_(2)O_(7).展开更多
The electronic structure and optical properties of Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7)(x¼0,1/8,2/8,3/8,4/8)were studied by first-principle calculations within the generalized gradient approximation approaches(GGA).Th...The electronic structure and optical properties of Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7)(x¼0,1/8,2/8,3/8,4/8)were studied by first-principle calculations within the generalized gradient approximation approaches(GGA).The lattice constants of Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7) increase with the increase of Ti^(4+)content caused by the substitution of Ti^(4+)with larger ionic radius for Mn^(4+).Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7) is a direct band gap semiconductor,and the band gap(Eg)increases with the increase of Ti^(4+)content.From the density of states,the introduction of Ti-3d states can weaken the effects of Mn-3d states on the bottom of conduction band and has little influence on O-2p states on the top of valence band.The introduction of nonmagnetic Ti^(4+)ions can weaken the magnetism of Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7).According to the Mulliken population analysis,it is found that the introduction of Ti^(4+)enhances the electronic accepting capacity of oxygen ions and enhances the electronic losing capacity of manganese ions.The bond strength of Ti–O covalent bond is stronger than that of Mn–O covalent bond.Furthermore,the optical properties of Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7) was calculated.As Ti^(4+)content increases,the absorption edge of Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7) has a blue shift,the static refractive index n0 decreases,the static dielectric constant"1(0)decreases,the position of loss peak moves to higher energy.展开更多
High-performance Pb(Zr_(1−x)Ti_(x))O_(3)(PZT)piezoceramics are urgently desired by the market in view of their expanded operating temperature range,reduced property temperature dependence,and enhanced sensitivity and ...High-performance Pb(Zr_(1−x)Ti_(x))O_(3)(PZT)piezoceramics are urgently desired by the market in view of their expanded operating temperature range,reduced property temperature dependence,and enhanced sensitivity and acoustic power.In this work,we reported a kind of low-cost and high-performance 0.06BiYbO_(3)–0.94Pb(Zr_(0.48)Ti_(0.52))O_(3) ternary piezoceramics;the modifying effects of La_(2)O_(3) on this perovskite system were investigated in terms of the structures,electrical properties,and thermal depolarization behaviors of ceramics.The field-dependent dielectric and conduction properties indicated that there are close correlations among oxygen vacancies(VO),conducting electrons,and intrinsic conduction process.The degradation in ferroelectric properties observed in those samples doped with more than 0.15 wt%of La_(2)O_(3) indicated that the occupying mechanisms of La^(3+)changed from the donor substitution for Pb^(2+)to the isovalent substitution for Bi^(3+).The thermally depoling micromechanisms of ceramics were revealed from the thermodynamic processes of defect dipoles and intrinsic dipoles within ferroelectric domains.The sample doped with 0.15 wt%of La_(2)O_(3) shows excellent electrical properties with TC=387℃,d33=332 pC/N,TKε=5.81×10^(−3)℃−1,Pr=20.66μC/cm^(2),Td=356℃.The significantly enhanced electrical properties and thermal depolarization temperature benefited from the donor substitution of La3+,decreasing the oxygen vacancy concentration in the lattice and possibly optimizing the ferroelectric domain structure of ceramics.展开更多
NASICON型快离子导体Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)(LATP)具有较高的离子电导率、较宽的电化学窗口及良好的水和空气稳定性,但其界面接触性能差。石榴石型Li_(7)La_(3)Zr_(2)O_(12)(LLZO)锂离子电导率高、电化学窗口较宽且热稳定...NASICON型快离子导体Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)(LATP)具有较高的离子电导率、较宽的电化学窗口及良好的水和空气稳定性,但其界面接触性能差。石榴石型Li_(7)La_(3)Zr_(2)O_(12)(LLZO)锂离子电导率高、电化学窗口较宽且热稳定性好,但其立方相结构不稳定,影响其实际应用。采用溶液浇筑法,制备纯PVDF-LiTFSI电解质膜和以PVDF为基、3种不同质量比的Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)的固态电解质膜,并探讨纯PVDF-LiTFSI电解质膜和3种不同质量比的活性无机电解质填料对复合固态电解质离子电导率的影响。结果表明,Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1时,电解质膜的XRD图谱的衍射峰比纯PVDF-LiTFSI下降更为明显,电化学窗口为3.9 V左右,表现出更好的稳定性。在不同温度下分别测量其离子电导率发现,Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1时的电解质膜均高于纯PVDF-LiTFSI电解质膜和Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为2∶1和3∶1时的电解质膜。将其装配成电池后发现,0.1C下电池首次充放电比容量分别为90 m A·h/g和87 m A·h/g。以0.5C的电流循环25圈,放电比容量从57 mA·h/g衰减至51mA·h/g,容量保持率为99.7%。所以,以PVDF为基、Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1的固态电解质膜有优良的倍率性能和循环稳定性能。展开更多
The piezotronics effect utilizes a piezopotential to modulate and control current in piezo-semiconductors.Ferroelectric materials,as a type of piezoelectric materials,possess piezoelectric coefficients that are signif...The piezotronics effect utilizes a piezopotential to modulate and control current in piezo-semiconductors.Ferroelectric materials,as a type of piezoelectric materials,possess piezoelectric coefficients that are significantly larger than those found in conventional piezoelectric materials.Here,we propose a strain modulated ferroelectric field-effect transistor(St-FeFET)utilizing external strain instead of gate voltage to achieve ferroelectric modulation,which eliminates the need for gate voltage.By applying a very small strain(0.01%),the St-FeFET can achieve a maximum on-off current ratio of 1250%and realizes a gauge factor(GF)of 1.19×10^(6),which is much higher than that of conventional strain sensors.This work proposes a new method for realizing highly sensitive strain sensors and presents innovative approaches to the operation methods of ferroelectric field-effect transistors as well as potential applications for coupling of strain sensors and various devices across different fields.展开更多
文摘采用快速液相烧结法制备Bi_(1-x)Pr_(x)Fe_(1-x)Ti_(x)O_(3)(x=0.00、0.03、0.06、0.12)系列多铁陶瓷样品,研究Pr-Ti共掺杂对BiFe O_(3)结构、缺陷、电学和磁学特性的影响。XRD分析结果表明:所有样品均为菱方钙钛矿结构,Pr-Ti共掺杂可有效抑制杂相生成,当掺杂量高于0.06时杂相基本消失,共掺杂引起结构畸变。正电子湮没寿命谱测试结果表明:所有样品中均存在阳离子空位型缺陷,空位尺寸和浓度均随Pr-Ti掺杂量增加而增大。电学和磁学性能测试结果表明:适量Pr-Ti共掺杂可有效提高Bi Fe O_(3)的介电、铁电和磁学性能。综合上述结果,认为BiFeO_(3)多铁性能的改善可能是由于Pr-Ti共掺杂引起晶格畸变、减少氧空位浓度、改变阳离子空位浓度等多种原因引起。
基金funded by the Natural Science Foundation of Sichuan Province(Grant No.2024NSFSC0219).
文摘Recently,high-performance lead zirconate titanate(Pb(Zr_(1-x)Ti_(x))O_(3),PZT)ferroelectric ceramics have attracted intensive attention due to their wider operating temperature range,better temperature stability,as well as larger piezoelectric properties and higher energy conversion efficiency.In this study,the perovskite-type ferroelectric ceramics with a chemical formula of Pb_(0.99-x)Gd_(0.01)Sr_(x)Zr_(0.53)Ti_(0.47)O_(3)(x=0 and 0.02,abbr.PGZT and PGSZT,respectively)were prepared by the traditional solid-state reaction route.The influences of Sr-doping on the phase structure,dielectric properties,ferroelectric properties and piezoelectric properties of the PGZT ceramics were comprehensively investigated.The field-dependent P–E hysteresis loops of PGSZT were measured in the frequency range of 0.05–10 Hz and temperature range of 20–100℃.The results show that Sr-doping not only enhances the dielectric permittivity and piezoelectric coefficient of PGZT,but also decreases its dielectric loss tangent,with the d_(33) value of 473 pC/N,ε_(r) value of 1586 and tanδvalue of 0.016 found in PGSZT.Also,PGSZT shows a high Curie temperature(T_(C))of 350℃.The underlying mechanisms of the property enhancement were identified as that the introduced Sr^(2+) replaces the volatile Pb^(2+) located at the A-site of the perovskite structure,thereby reducing the concentration of lead vacancies and promoting the grain growth of the ceramics,consequently enhancing the dielectric and piezoelectric properties of PGZT.On the other hand,the frequency change in the low-frequency range(<1 Hz)played a significant impact on the remanent polarization(P_(r))and internal biased electric field(E_(i))of PGSZT,but the frequency dependence of coercive field(E_(c))tends to diminish in the high-frequency range(≥1 Hz).
基金supported by the National Natural Science Foundation of China(No.51972143)supported by State Key Laboratory of New Ceramic and Fine Processing Tsinghua University(No.KFZD202101)。
文摘Pr_(2)(Zr_(1−x)Ti_(x))_(3)(MoO_(4))_(9)(x=0.1-1.0)ceramics were prepared via a conventional solid-state method,the dependence of crystal structure and bond characteristics on microwave dielectric properties was investigated systemically.The X-ray diffraction patterns indicated that the single-phase Pr_(2)Zr_(3)(MoO_(4))_(9)structure was formed in all the specimens.As the Ti^(4+)content increased,the lattice volume gradually decreased,which was ascribed to the fact that the ionic radius of Ti^(4+)was smaller than that of Zr^(4+).Notably,outstanding microwave dielectric properties withεr of 10.73-16.35,Q·f values of 80,696-18,726 GHz and minorτ_(f) values−14.1-−2.6 ppm/℃were achieved in Pr_(2)(Zr_(1−x)Ti_(x))_(3)(MoO_(4))_(9)ceramics.Theε_(r) increased with the rising x values,which was associated with the increase ofα/Vm values.The decreasing Q·f was affected by the decline of lattice energy of[Zr/TiO_(6)]octahedral.Theτf value was dominated by[Zr/TiO_(6)]octahedral distortion,Mo-O bond energy,bond strength and B-site bond valence.Furthermore,infrared reflection spectra suggested that the properties were mainly caused by the absorption of phonon,and the dielectric loss could be further reduced by optimizing the experimental process.
基金Project supported by the National High Technology Research and Development Program of China(2015AA034403)National Natural Science Foundation of China(51762036)The Science and Technology Program of Inner Mongolia(2019)。
文摘Rare earth Er^(3+)doped(Sm_(1-x)Er_(x))_(2)Zr_(2)O_(7)(x=0.1,0.2,and 0.3)ceramic samples were synthesized using a solid state reaction method.The microstructure and thermal properties of these ceramics were investigated to evaluate their potential as thermal barrier coating materials.The results show that ceramics are compact with regular-shaped grains of 1-5μm size.(Sm_(1-x)Er_(x))_(2)Zr_(2)O_(7)has a pyrochlore structure mainly determined by ionic radius ratio,but the ordering degree decreases with increase of the Er_(2)O_(3)content.There is no phase transformation from 1000 to 1200℃,and the(Sm_(1-x)Er_(x))_(2)Zr_(2)O_(7)ceramics exhibit excellent phase stability during thermal treatment at 1200℃for 100 h and 1400℃for 50 h.The thermal conductivities of dense(Sm_(1-x)Er_(x))_(2)Zr_(2)O_(7)ceramics range from 1.52 to 1.59 W/(m·K),which is lower than that of Sm_(2)Zr_(2)O_(7),and decrease as the Er2O3content increases.Besides,the thermal expansion coefficient of(Sm_(1-x)Er_(x))_(2)Zr_(2)O_(7)is higher than that of Sm_(2)Zr_(2)O_(7).
基金This work was supported by the Excellent Talent Project in University of Chongqing(Grant No.2017-35)the Program for Innovation Teams in University of Chongqing(Grant No.CXTDX201601032)+1 种基金he Science and Technology Innovation Project of Social Undertakings and People’s Livelihood Guarantee of Chongqing(Grant No.CSTC2017 shmsA90015)the Chongqing Research Program of Basic Research and Frontier Technology(Grant Nos.CSTC2018 jcyjAX0416,CSTC2016jcyjA0175 and CSTC2016jcyjA0349).
文摘The electronic structure and optical properties of Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7)(x¼0,1/8,2/8,3/8,4/8)were studied by first-principle calculations within the generalized gradient approximation approaches(GGA).The lattice constants of Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7) increase with the increase of Ti^(4+)content caused by the substitution of Ti^(4+)with larger ionic radius for Mn^(4+).Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7) is a direct band gap semiconductor,and the band gap(Eg)increases with the increase of Ti^(4+)content.From the density of states,the introduction of Ti-3d states can weaken the effects of Mn-3d states on the bottom of conduction band and has little influence on O-2p states on the top of valence band.The introduction of nonmagnetic Ti^(4+)ions can weaken the magnetism of Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7).According to the Mulliken population analysis,it is found that the introduction of Ti^(4+)enhances the electronic accepting capacity of oxygen ions and enhances the electronic losing capacity of manganese ions.The bond strength of Ti–O covalent bond is stronger than that of Mn–O covalent bond.Furthermore,the optical properties of Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7) was calculated.As Ti^(4+)content increases,the absorption edge of Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7) has a blue shift,the static refractive index n0 decreases,the static dielectric constant"1(0)decreases,the position of loss peak moves to higher energy.
基金This work was funded by the National Natural Science Foundation of China(Grant Nos.11702037 and 11832007)State Key Laboratory of Mechanics and Control of Mechanical Structures,Nanjing University of Aeronautics and astronautics(Grant No.MCMS-E-0522G01)+1 种基金the Open Foundation of Guangdong Provincial Key Laboratory of Materials and Technologies for Energy Conversion(Grant No.MATEC2022KF001)as well as the Cultivation Project for the Natural Science Foundation and Highlevel Talent at Chengdu University(Grant No.Z1350).
文摘High-performance Pb(Zr_(1−x)Ti_(x))O_(3)(PZT)piezoceramics are urgently desired by the market in view of their expanded operating temperature range,reduced property temperature dependence,and enhanced sensitivity and acoustic power.In this work,we reported a kind of low-cost and high-performance 0.06BiYbO_(3)–0.94Pb(Zr_(0.48)Ti_(0.52))O_(3) ternary piezoceramics;the modifying effects of La_(2)O_(3) on this perovskite system were investigated in terms of the structures,electrical properties,and thermal depolarization behaviors of ceramics.The field-dependent dielectric and conduction properties indicated that there are close correlations among oxygen vacancies(VO),conducting electrons,and intrinsic conduction process.The degradation in ferroelectric properties observed in those samples doped with more than 0.15 wt%of La_(2)O_(3) indicated that the occupying mechanisms of La^(3+)changed from the donor substitution for Pb^(2+)to the isovalent substitution for Bi^(3+).The thermally depoling micromechanisms of ceramics were revealed from the thermodynamic processes of defect dipoles and intrinsic dipoles within ferroelectric domains.The sample doped with 0.15 wt%of La_(2)O_(3) shows excellent electrical properties with TC=387℃,d33=332 pC/N,TKε=5.81×10^(−3)℃−1,Pr=20.66μC/cm^(2),Td=356℃.The significantly enhanced electrical properties and thermal depolarization temperature benefited from the donor substitution of La3+,decreasing the oxygen vacancy concentration in the lattice and possibly optimizing the ferroelectric domain structure of ceramics.
文摘NASICON型快离子导体Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)(LATP)具有较高的离子电导率、较宽的电化学窗口及良好的水和空气稳定性,但其界面接触性能差。石榴石型Li_(7)La_(3)Zr_(2)O_(12)(LLZO)锂离子电导率高、电化学窗口较宽且热稳定性好,但其立方相结构不稳定,影响其实际应用。采用溶液浇筑法,制备纯PVDF-LiTFSI电解质膜和以PVDF为基、3种不同质量比的Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)的固态电解质膜,并探讨纯PVDF-LiTFSI电解质膜和3种不同质量比的活性无机电解质填料对复合固态电解质离子电导率的影响。结果表明,Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1时,电解质膜的XRD图谱的衍射峰比纯PVDF-LiTFSI下降更为明显,电化学窗口为3.9 V左右,表现出更好的稳定性。在不同温度下分别测量其离子电导率发现,Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1时的电解质膜均高于纯PVDF-LiTFSI电解质膜和Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为2∶1和3∶1时的电解质膜。将其装配成电池后发现,0.1C下电池首次充放电比容量分别为90 m A·h/g和87 m A·h/g。以0.5C的电流循环25圈,放电比容量从57 mA·h/g衰减至51mA·h/g,容量保持率为99.7%。所以,以PVDF为基、Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1的固态电解质膜有优良的倍率性能和循环稳定性能。
基金supported by the National Natural Science Foundation of China(No.52192611)Beijing Municipal Natural Science Foundation(No.Z230024)the Fundamental Research Funds for the Central Universities.
文摘The piezotronics effect utilizes a piezopotential to modulate and control current in piezo-semiconductors.Ferroelectric materials,as a type of piezoelectric materials,possess piezoelectric coefficients that are significantly larger than those found in conventional piezoelectric materials.Here,we propose a strain modulated ferroelectric field-effect transistor(St-FeFET)utilizing external strain instead of gate voltage to achieve ferroelectric modulation,which eliminates the need for gate voltage.By applying a very small strain(0.01%),the St-FeFET can achieve a maximum on-off current ratio of 1250%and realizes a gauge factor(GF)of 1.19×10^(6),which is much higher than that of conventional strain sensors.This work proposes a new method for realizing highly sensitive strain sensors and presents innovative approaches to the operation methods of ferroelectric field-effect transistors as well as potential applications for coupling of strain sensors and various devices across different fields.
